TWI816645B - Organic electronic materials, organic layers, organic electronic components, organic electroluminescent components, display components, lighting devices and display devices - Google Patents

Abstract

An organic electronic material containing a charge transport compound having a structural site represented by formula (I) and a weight average molecular weight greater than 40,000; -Ar-X-Y-Z (I) In formula (I), Ar represents In the aryl group or heteroaryl group having 2 to 30 carbon atoms, X represents a linking group, Y represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and Z represents a substituted or unsubstituted polymerizable functional group.

Description

Organic electronic materials, organic layers, organic electronic components, organic electroluminescent components, display components, lighting devices and display devices

Embodiments of the present invention relate to an organic electronic material and an organic layer formed using the material. Furthermore, other embodiments of the present invention relate to an organic electronic element and an organic electroluminescent element, and a display element, a lighting device, and a display device using the organic electroluminescent element. The organic electronic element and the organic electroluminescent element Having the above-mentioned organic layer.

Organic electronic components are components that use organic substances to perform electrical operations. They are expected to take advantage of advantages such as energy saving, low price, and flexibility, and are attracting attention as a technology that can replace conventional inorganic semiconductors mainly composed of silicon. Examples of organic electronic elements include organic electroluminescent elements (hereinafter also referred to as "organic EL elements"), organic photoelectric conversion elements, organic transistors, and the like.

Organic EL elements are attracting attention, for example, in applications such as large-area solid-state light sources that serve as substitutes for incandescent lamps or gas-filled lamps. In addition, organic EL elements have attracted attention as the most powerful self-luminous display that can replace liquid crystal displays (LCD) in the field of flat panel displays (FPD), and have been commercialized.

Organic EL elements can be roughly classified into the following two types based on the organic materials used: low molecular organic EL elements and polymer organic EL elements. Polymer-type organic EL elements use polymer compounds as organic materials, while low-molecular-type organic EL elements use low-molecular compounds. On the other hand, the manufacturing methods of organic EL elements can be roughly divided into the following two types: dry process, which mainly performs film formation in a vacuum system; and wet process, which uses plate printing such as letterpress printing and gravure printing. Printing, inkjet and other plateless printing are used to form films. Because it can easily form a film, the wet process is expected to be an indispensable method for large-screen organic EL displays in the future.

Therefore, materials suitable for wet processes are being developed. For example, research has been conducted on forming a multilayer structure using a compound having a polymerizable functional group (see, for example, Patent Document 1 and Non-Patent Document 1). [Prior art documents] (Patent documents)

Patent document 1: Japanese Patent Application Publication No. 2006-279007 (non-patent document)

Non-patent literature 1: Kengo Hirose, Daisuke Kumaki, Nobuaki Koike, Akira Kuriyama, Seiichiro Ikehata, Seishi Toki, 53rd Joint Lecture on Relations in Applied Physics, 26p-ZK-4 (2006)

[Problems to be Solved by the Invention] Generally speaking, organic EL elements that are manufactured using a polymer compound and according to a wet process have the advantages of being easy to reduce costs and increase the area. However, organic EL devices having organic layers made of conventional polymer compounds are expected to be further improved in device characteristics such as driving voltage, luminous efficiency, and luminous lifetime.

In particular, conventional polymer compounds used as charge transport compounds have low thermal stability and are therefore prone to thermal deterioration. If the heat resistance of the polymer compound is insufficient, for example, the organic layer may be thermally degraded due to the high-temperature process used to manufacture the device, thus reducing its original performance, making it difficult to obtain the desired device characteristics. Among them, in the case of organic EL elements, for example, the driving voltage is likely to increase due to thermal deterioration of the organic layer during high-temperature baking processing. Therefore, it is desired to develop charge-transporting compounds having excellent heat resistance.

Embodiments of the present invention have been made in view of the above problems, and an object thereof is to provide an organic electronic material including a charge transport compound, and an organic layer using the material and having excellent heat resistance. Suitable for wet processes and has excellent heat resistance. Furthermore, another object of the present invention is to provide an organic electronic element and an organic EL element, and a display element, a lighting device, and a display device using the organic EL element. The organic electronic element and the organic EL element use the above-mentioned The organic layer has excellent heat resistance. [Technical means to solve problems]

The present inventors concentrated on research and found that a charge-transporting compound is suitable for wet processes, exhibits excellent heat resistance, and is suitable as an organic electronic material. The charge-transporting compound has a specific structure, thereby completing the present invention.

That is, an embodiment of the present invention relates to an organic electronic material containing a charge transport compound having a structural moiety represented by the following formula (I) and having a weight average molecular weight of greater than 40,000.

-Ar-X-Y-Z(I)

In formula (I), Ar represents an aryl group or heteroaryl group having 2 to 30 carbon atoms, X represents at least one linking group selected from the group consisting of the following formulas (x1) to (x10), and Y represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and Z represents a substituted or unsubstituted polymerizable functional group.

In formulas (x1) to (x10), R each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms.

In the organic electronic material of the above embodiment, the polymerizable functional group preferably includes a group selected from the group consisting of an oxetanyl group, an epoxy group, a vinyl group, an acrylyl group, and a methacrylyl group. At least 1 of them. In addition, the structural moiety represented by the above formula (I) is preferably located at the terminal of the charge transport compound.

In the organic electronic material of the above embodiment, the thermogravimetric reduction rate of the charge transport compound when heated to 300° C. is preferably 5% or less. The above-mentioned charge transport compound is preferably a hole injection layer material.

In the organic electronic material of the above embodiment, the charge transport compound preferably contains a divalent structural unit having charge transport properties. Furthermore, the charge-transporting compound preferably contains at least one selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a bithiophene structure, a benzene structure, a phenoxazine structure, and a fluorine structure. structure.

In the organic electronic material of the above embodiment, the charge transport compound preferably has a structure branching in three or more directions. Furthermore, the charge transport compound is preferably a charge transport polymer.

The organic electronic material according to the above embodiment preferably further contains a polymerization initiator. The above-mentioned polymerization initiator preferably contains a cationic polymerization initiator. The above-mentioned cationic polymerization initiator preferably contains an onium salt.

The organic electronic material according to the above embodiment preferably further contains a solvent. The above-mentioned solvent is preferably a non-polar solvent.

Another embodiment of the present invention relates to an organic layer formed of the organic electronic material of the above embodiment.

Another embodiment of the present invention relates to an organic electronic component including the above-mentioned organic layer.

Another embodiment of the present invention relates to an organic electroluminescent element including the above-mentioned organic layer. The organic electroluminescent element preferably has a light-emitting layer containing a phosphorescent material or a light-emitting layer containing a thermally activated delayed fluorescent material. The above-mentioned organic electroluminescent element preferably further has a flexible substrate or a resin film substrate.

Another embodiment of the present invention relates to a display element including the above-mentioned organic electroluminescent element.

Another embodiment of the present invention relates to a lighting device including the above-mentioned organic electroluminescent element.

Another embodiment of the present invention relates to a display device including the above-mentioned lighting device and a liquid crystal element as a display means. [Efficacy of the invention]

According to an embodiment of the present invention, it is possible to provide an organic electronic material that contains a charge transport compound that is suitable for a wet process and has excellent heat resistance. Furthermore, it is possible to provide an organic layer using the above-mentioned organic electronic material and having excellent heat resistance. Furthermore, according to other embodiments of the present invention, it is possible to provide an organic electronic element, an organic EL element, a display element, a lighting device, and a display device using the organic EL element, and the organic electronic element and the organic EL element can be provided by using The above-mentioned organic electronic materials are used to form organic layers and have excellent heat resistance. The disclosure of this case is related to the subject matter recorded in the International Patent Application No. PCT/JP2016/082991, and all the disclosure contents of this case are incorporated into this case by reference.

Hereinafter, embodiments of the present invention will be described.

<Organic Electronic Material> The organic electronic material according to the embodiment of the present invention is characterized by containing one or more types of charge-transporting compounds having a specific structural moiety represented by the following formula (I).

-Ar-X-Y-Z (I) In formula (I), Ar represents an aryl group or heteroaryl group having 2 to 30 carbon atoms, X represents a connecting group, Y represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and Z represents a hydrocarbon group. Substituted or unsubstituted polymerizable functional groups.

The organic electronic material may contain two or more charge-transporting compounds having the above-mentioned specific structural parts, and may further contain other charge-transporting compounds.

[Charge Transport Compound] The charge transport compound that is a feature of the present invention has one or more structural units having charge transport properties, and at least one of the structural units includes a structural moiety represented by the formula (I). Hereinafter, the structural parts represented by formula (I) will be described in detail.

In formula (I), Ar represents an aryl group or heteroaryl group having 2 to 30 carbon atoms. An aryl group means a group having a structure remaining after removing two hydrogen atoms from aromatic hydrocarbons. Heteroaryl group means a group having a structure remaining after removing two hydrogen atoms from an aromatic heterocyclic ring. Aromatic hydrocarbons and aromatic heterocycles may each have a single ring structure such as benzene or a fused ring structure in which rings are condensed with each other such as naphthalene.

Specific examples of aromatic hydrocarbons include benzene, naphthalene, anthracene, tetraphenyl, fentanyl, and phenanthrene. Specific examples of aromatic heterocycles include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, and oxadiene. Azoles, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene.

Aromatic hydrocarbons and aromatic heterocycles may be polycyclic structures composed of two or more selected from monocyclic and fused rings bonded via a single bond. Examples of aromatic hydrocarbons having such a polycyclic structure include biphenyl, terphenyl, and triphenylbenzene. Aromatic hydrocarbons and aromatic heterocycles are each unsubstituted or may have one or more substituents. The substituent may be, for example, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms. The carbon number is more preferably 1 to 15, still more preferably 1 to 12, and particularly preferably 1 to 6.

In one embodiment, Ar is preferably a phenylene group or a naphthylene group, and more preferably a phenylene group.

In formula (I), X is at least one linking group selected from the group consisting of the following formulas (x1) to (x10).

In formulas (x1) to (x10), R each independently represents a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms. In one embodiment, R is preferably a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms. The number of carbon atoms mentioned above is more preferably 2 to 16, still more preferably 3 to 12, and particularly preferably 4 to 8. In another embodiment, R is preferably an aryl group having 6 to 30 carbon atoms, more preferably a phenyl group or a naphthyl group, and still more preferably a phenyl group.

In one embodiment, the above-mentioned linking group X is preferably x1. That is, the charge transport compound preferably has a structural moiety represented by the following formula (I-1).

-Ar-O-Y-Z (I-1) In formula (I), Y is a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. The aliphatic hydrocarbon group may have a linear, branched, cyclic, or a combination of these structures. The aliphatic hydrocarbon group may be saturated or unsaturated.

In one embodiment, from the viewpoint of easy acquisition of monomers as raw materials, Y is preferably an aliphatic hydrocarbon group having a linear structure, and more preferably is saturated. From these viewpoints, in formula (I), Y is preferably -(CH ₂ ) _n -. That is, in one embodiment, the charge transport compound preferably has a structural moiety represented by the following formula (I-2).

-Ar-X-(CH ₂ ) _n -Z (I-2) In formula (I-2), n is 1 to 10, preferably 1 to 8, more preferably 1 to 6. From the viewpoint of heat resistance, n is more preferably 1 to 4, and n is 1 or 2.

As described above, the charge transport compound preferably has a structural moiety represented by at least one of the above formulas (I-1) and (I-2), and more preferably has a structural moiety represented by the following formula (I-3) structural parts.

-Ar-O-(CH ₂ ) _n -Z (I-3) In each of the above formulas, Z represents a polymerizable functional group. "Polymerizable functional group" refers to a functional group capable of forming a bond by applying heat and/or light. The polymerizable functional group Z may be unsubstituted or may have a substituent. Specific examples of the polymerizable functional group Z include groups having carbon-carbon multiple bonds (for example, vinyl, allyl, butenyl, ethynyl, acrylyl, methacrylyl, etc.), Groups with small member rings (such as cyclopropyl, cyclobutyl and other cyclic alkyl groups; epoxy (oxiranyl), oxetanyl (oxetanyl) )) and other cyclic ether groups; diketene group; sulfide group; lactone group; lactam group, etc.), heterocyclic groups (such as furyl, pyrrolyl, thienyl, silole ) base) etc.

As the polymerizable functional group Z, in particular, a vinyl group, an acryl group, a methacryl group, an epoxy group, and an oxetanyl group are preferred. From the viewpoint of reactivity and characteristics of organic electronic components, a vinyl group, an oxetanyl group, or an epoxy group is more preferred. These polymerizable functional groups may have substituents. The substituent is preferably a linear, cyclic or branched saturated alkyl group having 1 to 22 carbon atoms. The above carbon number is more preferably 1 to 8, still more preferably 1 to 4. The substituent is preferably a linear saturated alkyl group having 1 to 4 carbon atoms.

In one embodiment, from the viewpoint of storage stability, the polymerizable functional group Z is preferably an oxetanyl group represented by the following formula (z1). In formula (z1), R may be a hydrogen atom or a saturated alkyl group having 1 to 4 carbon atoms. R is particularly preferably methyl or ethyl.

The charge-transporting compound having at least one structural moiety represented by formula (I) contains at least one polymerizable functional group Z in its structure. Compounds containing polymerizable functional groups can be hardened through polymerization reactions, and can change their solubility in solvents through hardening. Therefore, a charge-transporting compound having at least one structural moiety represented by formula (I) can become a material that has excellent hardenability and is suitable for wet processes.

The charge-transporting compound in the present invention only needs to have a structural moiety represented by the above formula (I) and have the ability to transport charges. In one embodiment, the transferred charges are preferably holes. If it is a hole transport compound, it can be used as a material for the hole injection layer and the hole transport layer of an organic EL element, for example. Moreover, if it is an electron-transporting compound, it can be used as a material of an electron-transporting layer and an electron-injection layer. Moreover, if it is a compound capable of transporting both holes and electrons, it can be used as a material for a light-emitting layer, etc. In one embodiment, the charge transport compound is preferably used as a material for the hole injection layer and/or the hole transport layer, and more preferably is used as a material for the hole injection layer.

Furthermore, in one embodiment, from the viewpoint of heat resistance, the charge-transporting compound preferably has a thermogravimetric reduction rate when heated to 300° C. of 5 mass % or less relative to the mass before heating. The above-mentioned thermogravimetric reduction rate is more preferably 3.5 mass% or less. Furthermore, the thermal mass reduction rate is preferably 2.5 mass% or less, 1.5 mass% or less, and 1.0 mass% or less in this order, and most preferably is 0.5 mass%.

When a specific charge-transporting polymer described below is used as the charge-transporting compound, the thermogravimetric reduction rate of the material can be easily adjusted within the above range. Here, "the thermogravimetric reduction rate when heated to 300°C" refers to the thermogravimetric reduction rate (mass %) when a 10 mg sample is heated to 300°C in the air at a temperature rising condition of 5°C/min. ). The measurement of the thermogravimetric reduction rate can be carried out using a thermogravimetric-differential thermal analysis (TG-DTA) device.

The charge transport compound has one or more structural units having charge transport properties, and at least one of the above structural units has a structural moiety represented by the above formula (I). In one embodiment, the charge transport compound may have a structure branching in three or more directions. Charge-transporting compounds are roughly classified into low-molecular compounds composed of one structural unit and high-molecular compounds composed of a plurality of structural units, and any of these compounds may be used. The structural units constituting the charge-transporting compound will be described later.

When the charge-transporting compound is a low-molecular compound, it is preferable from the viewpoint of easily obtaining a high-purity material. When the charge-transporting compound is a polymer compound, it is preferable from the viewpoint of easy preparation of the composition and excellent film-forming properties. Furthermore, from the viewpoint of obtaining the advantages of both, a low molecular compound and a high molecular compound can be mixed and used as the charge transport compound. Hereinafter, as an example of a charge-transporting compound, a polymer compound composed of a plurality of structural units having charge-transporting properties will be described more specifically.

[Charge-transporting polymer] When the charge-transporting compound is a polymer compound, the charge-transporting compound may be a polymer or an oligomer. Hereinafter, these are collectively referred to as "charge transport polymers". The charge-transporting polymer has at least one structural site represented by the following formula (1) described above in its molecule.

-Ar-XYZ (I) A charge-transporting polymer containing a structural moiety represented by -Ar-CH ₂ -O- at its terminal end. It tends to break the bonds within the molecule easily by heating, resulting in a lack of heat resistance. sex. On the other hand, according to the embodiment of the present invention, the heat resistance of the charge transport polymer can be improved by configuring the charge transport polymer having the structural moiety represented by formula (I).

As the heat resistance improves, thermal degradation of the organic layer caused, for example, by high-temperature processes during device fabrication is improved, making it easier to maintain the performance of the organic layer. In particular, when the charge-transporting polymer of this embodiment is used to form the organic layer according to the coating method, even if a high-temperature baking treatment is applied, the performance degradation of the organic layer can be suppressed and high carrier mobility can be maintained.

The charge-transporting polymer may be linear or may have a branched structure. The charge-transporting polymer preferably contains at least a divalent structural unit L having charge transporting properties and a monovalent structural unit T constituting the terminal portion, and may further include a trivalent or higher structural unit B constituting the branch portion. The charge-transporting polymer may contain only one type of each structural unit, or may contain a plurality of types of each structural unit. In the charge-transporting polymer, each structural unit is bonded to each other at the bonding site of "monovalent" to "trivalent or higher".

(Structure of charge-transporting polymer) Examples of partial structures contained in the charge-transporting polymer include the following. The charge-transporting polymer is not limited to polymers having the following partial structures. In some structures, "L" represents structural unit L, "T" represents structural unit T, and "B" represents structural unit B. "*" indicates a site bonded to other structural units. In the following partial structures, the plurality of L's may be the same structural units or may be different structural units. The same goes for T and B.

Linear charge transport polymer

Charge transport polymer with branched structure

In one embodiment, the charge-transporting polymer is preferably a divalent structural unit L having charge-transporting properties. Furthermore, in one embodiment, the charge-transporting polymer preferably has a structure branching in three or more directions, that is, it has the above-mentioned structural unit B. The charge-transporting polymer preferably contains at least one structure selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a bithiophene structure, a benzene structure, a phenoxazine structure, and a fluorine structure. This structure is preferably included in the structural unit L described below, may be included in the structural unit B, or may be included in both the structural unit L and the structural unit B. When the charge-transporting polymer contains any of the above structures, the charge-transporting property, especially the hole-transporting property, can be improved.

In one embodiment, the charge-transporting polymer only needs to include a structural moiety represented by formula (1) in at least one of the structural units L, B, and T constituting the polymer, and its introduction position is not particularly limited. . In a preferred embodiment, from the viewpoint of improving sclerosis, the structural moiety represented by formula (I) is preferably present in the structural unit T constituting at least one terminal portion of the charge transport polymer. From the viewpoint of easy synthesis of the monomer compound constituting the charge transport polymer, the structural moiety represented by formula (I) is preferably present in the structural unit T constituting the terminal portion. Hereinafter, the structural units of the charge transport polymer will be described in more detail.

(Structural unit L) The structural unit L is a divalent structural unit having charge transport properties. The structural unit L is not particularly limited as long as it contains an atomic group capable of transporting charges. For example, the structural unit L is selected from the following substituted or unsubstituted structures: aromatic amine structure, carbazole structure, thiophene structure, fluorine structure, benzene structure, biphenyl structure, terphenyl structure, naphthalene structure, anthracene structure Structure, condensed tetraphenyl structure, phenanthrene structure, dihydrophenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxaline structure, acridine structure, phenanthrene structure, furan Structure, pyrrole structure, oxazole structure, oxadiazole structure, thiazole structure, thiadiazole structure, triazole structure, benzothiophene structure, benzoxazole structure, benzoxadiazole structure, benzothiazole structure, benzene Thiadiazole structure, benzotriazole structure, and structures including one or more of these structures. The aromatic amine structure is preferably a triarylamine structure, and more preferably a triphenylamine structure.

In one embodiment, from the viewpoint of obtaining excellent hole transport properties, the structural unit L is preferably selected from the following substituted or unsubstituted structures: aromatic amine structure, carbazole structure, thiophene structure, fluorine structure structure, benzene structure, pyrrole structure, and structures containing one or more of these structures; more preferably, they are selected from the following substituted or unsubstituted structures: aromatic amine structure, carbazole structure, And include one or more structures among these structures. In another embodiment, from the viewpoint of obtaining excellent electron transport properties, the structural unit L is preferably selected from the following substituted or unsubstituted structures: fluorine structure, benzene structure, phenanthrene structure, pyridine structure, quinine structure phyline structure, and structures containing one or more of these structures.

Specific examples of the structural unit L include the following. The structural unit L is not limited to the following examples.

R each independently represents a hydrogen atom or a substituent. When R is a substituent, it is preferred that R can each independently be a substituent selected from the group consisting of: -R ¹ (except hydrogen atoms), -OR ² , -SR ³ , -OCOR ⁴ , -COOR ⁵ , -SiR ⁶ R ⁷ R ⁸ , halogen atoms, and groups containing polymerizable functional groups. R ¹ to R ⁸ of the above substituents each independently represent: a hydrogen atom; a linear, cyclic or branched alkyl group with 1 to 22 carbon atoms; or an aryl or heteroaryl group with 2 to 30 carbon atoms . An aryl group is an atomic group remaining after removing one hydrogen atom from aromatic hydrocarbons. A heteroaryl group is an atomic group remaining after removing one hydrogen atom from an aromatic heterocyclic ring. The alkyl group may be further substituted with an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group may be further substituted with a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms. R is preferably a hydrogen atom or a substituent selected from the group consisting of an alkyl group, an aryl group and an aryl group substituted by an alkyl group. In one embodiment, from the viewpoint of increasing the molecular weight of the polymer, R is more preferably a substituent. When R is a substituent, the molecular weight of the charge-transporting polymer is easily increased, and excellent heat resistance is easily obtained. In one embodiment, the charge transport polymer is used with a non-polar solvent. Examples of nonpolar solvents include benzene, toluene, ethyl acetate, dioxane, tetrahydrofuran, and the like. In general, polymers tend to lose solubility in non-polar solvents as their molecular weight increases. In contrast, when the molecular weight of the polymer is increased by introducing a substituent, a decrease in solubility can be easily suppressed. Ar represents an aryl group or heteroaryl group having 2 to 30 carbon atoms. An aryl group is an atomic group remaining after removing two hydrogen atoms from aromatic hydrocarbons. A heteroaryl group is an atomic group remaining after removing two hydrogen atoms from an aromatic heterocyclic ring. Ar is preferably an aryl group, more preferably a phenyl group.

Examples of aromatic hydrocarbons include a monocyclic ring, a fused ring, or a polycyclic ring in which two or more selected from the group consisting of a monocyclic ring and a fused ring are bonded via a single bond. Examples of the aromatic heterocyclic ring include a monocyclic ring, a fused ring, or a polycyclic ring in which two or more selected from the group consisting of a monocyclic ring and a fused ring are bonded via a single bond.

(Structural unit B) When the charge-transporting polymer has a branched structure, the structural unit B is a trivalent or higher structural unit constituting the branched portion. From the viewpoint of improving the durability of organic electronic components, the structural unit B preferably has a valence of 6 or less, and more preferably has a valence of 3 or 4. Structural unit B is preferably a unit with charge transport properties. For example, from the perspective of improving the durability of organic electronic components, structural unit B is selected from the following substituted or unsubstituted structures: aromatic amine structure, carbazole structure, condensed polycyclic aromatic hydrocarbons structure, and structures containing one or more of these structures.

Specific examples of the structural unit B include the following examples. Structural unit B is not limited to the following examples.

W represents a trivalent linking group, for example, an aromatic hydrocarbon triyl group or a heteroaromatic hydrocarbon triyl group having 2 to 30 carbon atoms. Aromatic triradicals are the atomic groups remaining after removing three hydrogen atoms from aromatic hydrocarbons. The heteroaromatic triyl group is the atomic group remaining after removing three hydrogen atoms from an aromatic heterocyclic ring. Ar each independently represents a divalent linking group, for example, each independently represents an aryl group or heteroaryl group having 2 to 30 carbon atoms. Ar is preferably an aryl group, more preferably a phenyl group. Y represents a divalent linking group. For example, one hydrogen atom is removed from a group having at least one hydrogen atom among R in the structural unit L (excluding a group containing a polymerizable functional group). The remaining 2-valent group. Z represents any one of a carbon atom, a silicon atom, and a phosphorus atom. In the structural unit, the benzene ring and Ar may have substituents. Examples of the substituent include the substituents described as R in the structural unit L.

(Structural unit T) The structural unit T is a monovalent structural unit constituting the terminal portion of the charge transport polymer. From the viewpoint of improving curability, the charge-transporting polymer preferably has a polymerizable functional group at its terminal portion. In one embodiment, the charge-transporting polymer preferably contains a structural unit T1 having a structure represented by the following formula (I). In formula (1), Ar, X, Y, and Z are as described previously.

-Ar-X-Y-Z (I) By using the charge-transporting polymer containing the above-mentioned structural unit T1, excellent hardening properties and heat resistance can be easily obtained. Structural unit T1 preferably has at least one of the formulas (I-1) and (I-2) shown above. Structural unit T1 preferably has the structure of formula (I-3) as shown above.

The charge-transporting polymer may further contain a monovalent structural unit constituting the terminal portion that is different from the above-mentioned structural unit T1 within the range that the charge-transporting property and curability are not reduced.

In one embodiment, in addition to the above-mentioned structural unit T1, the charge-transporting polymer may further include a monovalent structural unit T2 having a structure represented by the following formula (II). When the charge-transporting polymer has the structural unit T1 and the structural unit T2, the heat resistance can be easily further improved.

-Ar-J-R1 (II) In formula (II), Ar represents a phenylene group or heteroaryl group having 2 to 30 carbon atoms.

J represents a single bond or any divalent linkage selected from the group consisting of an ester bond (-COO-) and (x1) to (x10) previously exemplified as the linking group X in formula (I) base.

In the above-mentioned linking group, R represents a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group having 6 to 30 carbon atoms.

In one embodiment, Ar in formula (II) is preferably an aryl group having 6 to 30 carbon atoms. More preferably, it is a phenylene group or a naphthylene group, and still more preferably, it is a phenylene group.

In one embodiment, J in formula (II) is preferably a single bond, an ester bond, or a linking group (-NR-) having a structure remaining after removing one hydrogen atom from the amine group. Here, in the above-mentioned linking group (-NR-), R is preferably a phenyl group.

In one embodiment, R1 in formula (II) is a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, preferably 2 to 16 carbon atoms, even more preferably 3 to 12 carbon atoms, and particularly preferably It’s 4 to 8.

In order to improve the heat resistance of the charge transport polymer, it is preferable to increase the proportion of ring structures contained in the molecule. From this viewpoint, in one embodiment, R1 in the above formula (II) is preferably a cyclic alkyl group (cycloalkyl group) having 3 to 30 carbon atoms. The carbon number is more preferably 5 to 20, further more preferably 6 to 15. The cycloalkyl group may be saturated or unsaturated, preferably saturated. Moreover, it may have either a monocyclic or a polycyclic structure, and it is more preferable to have a polycyclic structure. Specific examples of R1 include adamantyl.

In another embodiment, R1 in the above formula (II) is preferably an aryl group having 6 to 30 carbon atoms, more preferably a phenyl group or a naphthyl group, and still more preferably a phenyl group.

Although not particularly limited, in one embodiment, the structural unit T2 preferably has the following structure: J in the above formula (II) is an ester bond, and R1 is a cycloalkyl group.

In one embodiment, from the viewpoint of improving both the hardening property and the heat resistance of the charge-transporting polymer, based on all the structural units T, the proportion of structural units T1 having the structure represented by formula (I) is relatively high. Preferably, it is 50 mol% or more, More preferably, it is 75 mol% or more, More preferably, it is 85 mol% or more. The proportion of the above-mentioned structural unit T1 can also be set to 100 mol%.

In one embodiment, from the viewpoint of further improving the heat resistance of the charge-transporting polymer, it is preferable to use the structural unit T2 in addition to the structural unit T1. At this time, based on all the structural units T (T1 + T2), the proportion of the structural unit T2 is preferably 75 mol% or less, more preferably 50 mol% or less, and still more preferably 25 mol% or less. On the other hand, the proportion of the structural unit T1 is preferably 25 mol% or more, more preferably 50 mol% or more, and still more preferably 75 mol% or more. By adjusting the ratio of the structural units T1 and T2 within the above range, the heat resistance can be further improved without reducing the hardenability.

From the viewpoint of contributing to changing the solubility, the polymerizable functional group is preferably contained in a large amount in the charge-transporting polymer. On the other hand, the polymerizable functional group is preferably contained in a small amount in the charge transport polymer from the viewpoint of not impairing the charge transport properties. The content of the polymerizable functional group can be appropriately set taking these viewpoints into consideration.

For example, from the viewpoint of being able to sufficiently change the solubility, the number of polymerizable functional groups per molecule of the charge transport polymer is preferably 2 or more, more preferably 3 or more. Furthermore, from the viewpoint of maintaining charge transport properties, the number of polymerizable functional groups is preferably 1,000 or less, more preferably 500 or less. Here, the number of polymerizable functional groups means the total amount of the polymerizable functional group Z and other polymerizable functional groups contained in the structural part represented by formula (1).

The number of polymerizable functional groups per molecule of the charge transport polymer can be determined by using the ratio of the amount of the monomer having the polymerizable functional group fed to the amount of the monomer corresponding to each structural unit, the charge transport polymer The weight average molecular weight, etc., is calculated as an average value, where these monomers are used to synthesize the charge transport polymer.

In addition, the number of polymerizable functional groups can be determined by using the ratio of the integrated value of the signal originating from the polymerizable functional group in the ¹ HnmR (nuclear magnetic resonance) spectrum of the charge transport polymer to the integrated value of the entire spectrum, the charge transport polymer The weight average molecular weight of the substance is calculated as an average value. Since it is simpler, when the feed amount is clear, it is better to use the value calculated using the feed amount.

(Number Average Molecular Weight) The number average molecular weight of the charge transport polymer can be appropriately adjusted taking into consideration the solubility in a solvent, film-forming properties, and the like. From the viewpoint of excellent charge transport properties, the number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and still more preferably 2,000 or more. Furthermore, from the viewpoint of maintaining good solubility in solvents and making it easy to prepare an ink composition, the number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, and still more preferably 50,000 or less.

(Weight Average Molecular Weight) The weight average molecular weight of the charge transport polymer can be appropriately adjusted taking into consideration the solubility in a solvent, film-forming properties, and the like. From the viewpoint of excellent charge transport properties, the weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, and still more preferably 10,000 or more. From the viewpoint of easily obtaining excellent heat resistance, it is preferably more than 40,000, more preferably 41,000 or more. In addition, from the viewpoint of maintaining good solubility in solvents and making it easy to prepare an ink composition, the weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, and still more preferably 400,000 or less.

The number average molecular weight and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene under the following conditions. Liquid delivery pump: L-6050, Hitachi High-Technologies Co., Ltd. UV-Vis detector: L-3000, Hitachi High-Technologies Co., Ltd. Column: Gelpack (registered trademark), GL-A160S/GL-A150S, Hitachi Chemical Co., Ltd. Eluate: THF (for HPLC, without stabilizer), Wako Pure Chemical Industries, Ltd. Flow rate: 1mL/min Column temperature: room temperature Molecular weight standard material: standard polystyrene

(Proportion of structural units) From the viewpoint of obtaining sufficient charge transport properties, the proportion of structural units L contained in the charge transport polymer is preferably 10 mol% or more based on all structural units. More preferably, it is 20 mol% or more, and further more preferably, it is 30 mol% or more. Furthermore, when considering the structural unit T and the structural unit B introduced as needed, the ratio of the structural unit L is preferably 95 mol% or less, more preferably 90 mol% or less, and still more preferably 85 mol% or less. .

From the viewpoint of improving the characteristics of organic electronic devices, or from the viewpoint of suppressing viscosity increase and enabling favorable synthesis of the charge transport polymer, the structural units contained in the charge transport polymer are based on all structural units. The ratio of T is preferably 5 mol% or more, more preferably 10 mol% or more, and still more preferably 15 mol% or more. Moreover, from the viewpoint of obtaining sufficient charge transport properties, the proportion of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less. In one embodiment, the proportion of the structural unit T means the proportion of the structural unit T1 having the structural moiety represented by formula (I). In another embodiment, the ratio of the structural unit T means the total amount of the above-mentioned structural unit T1 and the structural unit T2 other than the structural unit T1.

When the charge-transporting polymer contains the structural unit B, from the viewpoint of improving the durability of the organic electronic device, the proportion of the structural unit B based on all the structural units is preferably 1 mol% or more, more preferably It is 5 mol% or more, and it is more preferable that it is 10 mol% or more. In addition, from the viewpoint of suppressing an increase in viscosity and favorably carrying out the synthesis of the charge transport polymer, or from the viewpoint of obtaining sufficient charge transport properties, the proportion of the structural unit B is preferably 50 mol% or less, more preferably 40 Mol% or less, more preferably 30 Mol% or less.

From the viewpoint of efficiently hardening the charge transport polymer, the proportion of the polymerizable functional groups in the charge transport polymer is preferably 0.1 mol% or more based on all structural units, more preferably It is 1 mol% or more, more preferably, it is 3 mol% or more. Moreover, from the viewpoint of obtaining good charge transport properties, the proportion of the polymerizable functional group is preferably 70 mol% or less, more preferably 60 mol% or less, and still more preferably 50 mol% or less. In addition, the "ratio of a polymerizable functional group" here means the ratio of the structural unit which has a polymerizable functional group with respect to all structural units. When the charge-transporting polymer further has a polymerizable functional group Z' in addition to the polymerizable functional group Z contained in the structural part of formula (I), it means that the structural unit having the polymerizable functional group Z and Z' The ratio of the total amount to all structural units.

When considering the balance of charge transport properties, durability, productivity, etc., the ratio (molar ratio) of the structural unit L and the structural unit T is preferably L:T=100:1 to 70, more preferably 100:3 to 50, and even better is 100:5~30. Moreover, when the charge transporting polymer contains the structural unit B, the ratio (molar ratio) of the structural unit L, the structural unit T and the structural unit B is preferably L:T:B=100:10～200:10～100 , more preferably 100:20～180:20～90, further more preferably 100:40～160:30～80.

The ratio of the structural units can be determined using the amount of feed of the monomer used to synthesize the charge-transporting polymer corresponding to each structural unit. In addition, the ratio of the structural unit can be calculated as an average value using the integrated value of the spectrum derived from each structural unit in the ¹ HnmR spectrum of the charge transport polymer. Since it is simpler, when the feed amount is clear, it is better to use the value calculated using the feed amount.

When the charge-transporting polymer is a hole-transporting material, from the viewpoint of obtaining higher hole-injection properties and hole-transportation properties, a compound having the following units as the main structural unit is preferred: having an aromatic A unit with an amine structure and/or a unit with a carbazole structure. From this point of view, the ratio of the total number of units having an aromatic amine structure and/or units having a carbazole structure to the number of all structural units in the polymer compound (excluding terminal structural units) is preferably 40 % or more, more preferably 45% or more, further more preferably 50% or more. The proportion of the total number of units having an aromatic amine structure and/or units having a carbazole structure can also be set to 100%.

(Production method) The charge transport polymer can be produced by various synthesis methods and is not particularly limited. For example, the following conventional coupling reactions can be used: Suzuki coupling, Negishi coupling, Enato coupling, Stille coupling, Buchwald-Hartwig coupling, etc. Suzuki coupling uses a Pd catalyst to produce a cross-coupling reaction between aromatic boronic acid derivatives and aromatic halides. By using Suzuki coupling, a charge-transporting polymer can be easily produced by bonding desired aromatic rings to each other.

In the coupling reaction, for example, Pd(0) compounds, Pd(II) compounds, Ni compounds, etc. are used as catalysts. In addition, a catalyst species can also be used, which is produced by using ginseng (diphenylmethylacetone) dipalladium (0), palladium (II) acetate, etc. as a precursor and coordinating with a phosphine base mix. Regarding the synthesis method of the charge transport polymer, for example, the description of International Publication No. WO2010/140553 can be referred to.

[Dopant] The organic electronic material may further contain a dopant. The dopant is not particularly limited as long as it is a compound that can enhance charge transport by being added to an organic electronic material to exhibit a doping effect. There are p-type doping and n-type doping in doping. P-type doping uses a substance that can function as an electron acceptor as a dopant, and n-type doping uses a substance that can function as an electron donor. substances as dopants. To improve the hole transportability, it is better to implement p-type doping, and to improve the electron transportability, it is better to implement n-type doping. The dopant used in the organic electronic material may be a dopant that exhibits the effect of either p-type doping or n-type doping. In addition, one type of dopant may be added alone, or a plurality of types of dopants may be mixed and added.

The dopant used for p-type doping is an electron-accepting compound, and examples thereof include Lewis acids, protonic acids, transition metal compounds, ionic compounds, halogen compounds, and π-conjugated compounds. Specifically, examples of Lewis acids include FeCl ₃ , PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₃ , BBr _{3 ,} etc. Examples of protonic acids include HF, HCl, HBr, HNO ₅ , H ₂ SO ₄ , HClO ₄ and other inorganic acids; benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, polyethylenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, 1-butanesulfonate Acid, vinylbenzenesulfonic acid, camphorsulfonic acid and other organic acids; as transition metal compounds, examples include: FeOCl, TiCl ₄ , ZrCl 4 , HfCl ₄ , NbF ₅ , AlCl ₃ , NbCl _{5 ,} TaCl ₅ , MoF ₅ ; as Examples of ionic compounds include: 4(pentafluorophenyl)borate ion, tris(trifluoromethanesulfonyl)methide ion, bis(trifluoromethanesulfonyl)imide ion, hexafluoromethanesulfonyl methide ion, Salts of perfluorinated anions such as fluorantimonate ion, AsF ₆ ^- (hexafluoroarsenate ion), BF ₄ ^- (tetrafluoroborate ion), PF ₆ ^- (hexafluorophosphate ion), and conjugate bases having the above protonic acids as salts of anions, etc.; as halogen compounds, examples include: Cl ₂ , Br ₂ , I ₂ , ICl, ICl ₃ , IBr, IF, etc.; as π-conjugated compounds, examples include: TCNE (tetracyanoethylene), TCNQ (tetracyanoquinodimethane), etc. Furthermore, electron-accepting compounds described in Japanese Patent Application Laid-Open No. 2000-36390, Japanese Patent Application Laid-Open No. 2005-75948, Japanese Patent Application Laid-Open No. 2003-213002, etc. can also be used.

Lewis acids, ionic compounds, π-conjugated compounds, etc. are preferred, and ionic compounds are more preferred. Among the ionic compounds, onium salts are particularly preferred. Onium salt refers to a compound composed of a cationic part containing onium ions such as iodonium and ammonium and an opposite anionic part.

The dopant used for n-type doping is an electron-pushing compound. Examples include: alkali metals such as Li and Cs; alkaline earth metals such as Mg and Ca; alkali metals and/or alkaline earth metals such as LiF and Cs ₂ CO ₃ Salts; metal complexes; electron-pushing organic compounds, etc.

In order to easily change the solubility of the organic layer, it is preferable to use a compound that can act as a polymerization initiator on the polymerizable functional group as a dopant. Examples of substances that have both functions as a dopant and a polymerization initiator include the above-mentioned ionic compounds.

[Other optional components] The organic electronic material may further contain charge-transporting low-molecular compounds, other charge-transporting polymers, etc.

[Content] From the viewpoint of obtaining good charge transport properties, the content of the charge transport compound is preferably 50 mass % or more, more preferably 70 mass % or more, and further more preferably 50 mass % or more, based on the total mass of the organic electronic material. More than 80% by mass. It can also be set to 100 mass%.

When a dopant is contained, from the perspective of improving the charge transport properties of the organic electronic material, its content is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, relative to the total mass of the organic electronic material. Further more Preferably, it is 0.5 mass % or more. In addition, from the viewpoint of maintaining good film-forming properties, the content is preferably 50 mass% or less, more preferably 30 mass% or less, and still more preferably 20 mass% or less based on the total mass of the organic electronic material.

[Polymerization Initiator] The organic electronic material of this embodiment preferably contains a polymerization initiator. As the polymerization initiator, conventional radical polymerization initiators, cationic polymerization initiators, anionic polymerization initiators, and the like can be used. From the viewpoint of being able to easily prepare the ink composition, it is preferable to use a substance that has both functions as a dopant and a function as a polymerization initiator. For example, the onium salt described above can be suitably used as a cationic polymerization initiator that also functions as a dopant. Examples include salts of perfluoride anions and cations such as iodon ions or ammonium ions. Specific examples of onium salts include the following compounds.

<Ink composition> The organic electronic material may be an ink composition in which the organic electronic material of the above embodiment further contains a solvent capable of dissolving or decomposing the material. By configuring and using such an ink composition, the organic layer can be easily formed using a simple method such as a coating method.

[Solvent] As the solvent, water, organic solvents, or mixed solvents thereof can be used. Examples of organic solvents include: alcohols such as methanol, ethanol, and isopropyl alcohol; alkanes such as pentane, hexane, and octane; cyclic alkanes such as cyclohexane; benzene, toluene, xylene, mesitylene, Aromatic hydrocarbons such as tetralin and diphenylmethane; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2 -Dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-di Aromatic ethers such as methyl anisole and 2,4-dimethylanisole; aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate; phenyl acetate, propyl acetate Aromatic esters such as phenyl acid ester, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; N,N-dimethylformamide, N,N-dimethylacetyl Amide solvents such as amines; dimethyl styrene, tetrahydrofuran, acetone, chloroform, methylene chloride, etc. Preferred are aromatic hydrocarbons, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers, and the like.

[Additive] The ink composition may further contain additives as optional components. Examples of additives include polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, antioxidants, anti-reducing agents, oxidizing agents, reducing agents, surface modifiers, emulsifiers, and defoaming agents. , dispersants, surfactants, etc.

[Content] The content of the solvent in the ink composition can be determined considering application to various coating methods. For example, the content of the solvent is preferably such that the ratio of the charge-transporting polymer to the solvent is 0.1% by mass or more, more preferably, the ratio of the charge-transporting polymer to the solvent is 0.2% by mass or more, and more preferably Preferably, the ratio of the charge-transporting polymer to the solvent is 0.5% by mass or more. Moreover, the content of the solvent is preferably an amount in which the ratio of the charge transport polymer to the solvent is 20 mass % or less, more preferably an amount in which the charge transport polymer is 15 mass % or less, and further more. Preferably, the ratio of the charge-transporting polymer to the solvent is 10% by mass or less.

<Organic Layer> The organic layer according to the embodiment of the present invention is a layer formed using the organic electronic material according to the above-mentioned embodiment. The organic electronic material according to the above embodiment can be used as an ink composition. By using the ink composition, the organic layer can be formed favorably by the coating method. Examples of coating methods include: spin coating method; casting method; dipping method; plate printing methods such as letterpress printing, concave mold printing, offset printing, offset printing, letterpress reverse offset printing, screen printing, and gravure printing; Commonly known methods such as inkjet printing and other plateless printing methods. When the organic layer is formed by a coating method, a hot plate or an oven can be used to dry the organic layer (coating layer) obtained after coating to remove the solvent.

The solubility of the organic layer can be changed by polymerizing the charge transport compound by irradiation, heat treatment, or the like. By laminating organic layers whose solubility has been changed, it is possible to easily create multilayered organic electronic devices. Regarding the formation method of the organic layer, for example, the description of International Publication No. WO2010/140553 can be referred to. According to the present invention, the above-mentioned heat treatment (also called high-temperature baking treatment) can be performed at a temperature exceeding 200° C., and thermal deterioration of the organic layer after the heat treatment can be suppressed.

From the viewpoint of improving the efficiency of charge transport, the thickness of the dried or hardened organic layer is preferably 0.1 nm or more, more preferably 1 nm or more, and still more preferably 3 nm or more. Furthermore, from the viewpoint of reducing resistance, the thickness of the organic layer is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 100 nm or less.

<Organic Electronic Device> The organic electronic device according to the embodiment of the present invention has at least the organic layer of the above-mentioned embodiment. Examples of organic electronic elements include organic EL elements, organic photoelectric conversion elements, organic transistors, and the like. The organic electronic element preferably has a structure in which an organic layer is arranged between at least a pair of electrodes.

[Organic EL element] An organic EL element according to an embodiment of the present invention has at least the organic layer of the above-mentioned embodiment. Organic EL elements usually have a light-emitting layer, an anode, a cathode and a substrate, and may have other functional layers such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer as needed. Each layer can be formed by evaporation or coating. The organic EL element preferably has an organic layer as a light-emitting layer or other functional layer, more preferably has an organic layer as a functional layer, and further preferably has an organic layer as a hole injection layer and a hole transport layer. of at least 1 species.

FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element according to an embodiment of the present invention. The organic EL element in Figure 1 is an element with a multi-layer structure, and has in order: a substrate 8, an anode 2, a hole injection layer 3 and a hole transport layer 6 composed of the organic layers of the above embodiment, a light-emitting layer 1, Electron transport layer 7, electron injection layer 5, and cathode 4. Each layer is described below.

In FIG. 1 , for example, the hole injection layer 3 and the hole transport layer 6 are organic layers formed using the above-mentioned organic electronic materials. However, the organic EL according to the embodiment of the present invention is not limited to such a structure, and other organic layers may be organic layers formed using the above-mentioned organic electronic materials.

[Light-emitting layer] As a material used in the light-emitting layer, light-emitting materials such as low molecular compounds, polymers, and dendrimers can be used. Polymers are preferred because they have high solubility in solvents and are suitable for coating methods. Examples of light-emitting materials include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescent materials (TADF), and the like.

Examples of fluorescent materials include perylene, coumarin, rubrene, quinacridone, stilbene, dyes for dye lasers, aluminum complexes, derivatives thereof, etc. Low molecular compounds; polymers such as polyfluoride, polyphenylene, polyphenylene vinylene, polyvinylcarbazole, fluorine-benzothiadiazole copolymer, fluorine-triphenylamine copolymer, and their derivatives; Mixtures of these.

As the phosphorescent material, metal complexes containing metals such as Ir and Pt can be used. Examples of the Ir complex include FIr(pic)(bis[(4,6-difluorophenyl)pyridine-N,C ² ]iridium picolinate (bis[(4,6)) which emits blue light. -difluorophenyl)pyridinato -N,C ² ]picolinatoiridium)(III)), Ir(ppy) ₃ (facial ginseng (2-phenylpyridine)iridium) that emits green light, (btp) ₂ Ir( that emits red light) acac) (bis[2-(2'-benzo[4,5-α]thienyl)pyridine-N,C ³ ](acetyl acetone)iridium), Ir(piq) ₃ (see (1-benzene) Base isoquinoline) iridium) etc. Examples of Pt complexes include PtOEP (2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum (2,3,7, 8,12,13,17,18-octaethyl -21H,23H-porphin platinum)), etc.

When the light-emitting layer contains a phosphorescent material, it is preferable that it further contains a host material in addition to the phosphorescent material. As the host material, low molecular compounds, polymers, or dendrimers can be used. Examples of low molecular compounds include CBP (4,4'-bis(9H-carbazol-9-yl)biphenyl), mCP (1,3-bis(9-carbazolyl)benzene), CDBP ( 4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), derivatives thereof, etc.; examples of polymers include the organic electronic materials of the above embodiments, polyethylene Carbazole, polyphenylene, polyfluoride, and their derivatives, etc.

Examples of thermally activated delayed fluorescent materials include compounds described in the following documents: Adv. Mater., 21, 4802-4906 (2009); Appl. Phys. Lett., 98, 083302 (2011); Chem. Comm., 48, 9580 (2012); Appl. Phys. Lett., 101, 093306 (2012); J. Am. Chem. Soc., 134, 14706 (2012); Chem. Comm., 48, 11392 (2012) ); Nature, 492, 234 (2012); Adv. Mater., 25, 3319 (2013); J. Phys. Chem. A, 117, 5607 (2013); Phys. Chem. Chem. Phys., 15, 15850 (2013); Chem. Comm., 49, 10385 (2013); Chem. Lett., 43, 319 (2014), etc.

[Hole Transport Layer, Hole Injection Layer] In Figure 1, the hole injection layer 3 and the hole transport layer 6 are organic layers formed using the above-mentioned organic electronic materials, but the organic EL element of the embodiment is not limited to this. structure, other organic layers can also be organic layers formed using the above-mentioned organic electronic materials. It is preferable to use it as at least one of a hole injection layer and a hole transport layer formed using the organic electronic material, and it is more preferable to use it as at least a hole injection layer. For example, when the organic EL element has an organic layer formed using the above-mentioned organic material as a hole transport layer, and further has a hole injection layer, conventional materials can be used for the hole injection layer. For example, when the organic EL element has an organic layer formed using the above-mentioned organic material as a hole injection layer, and further has a hole transport layer, conventional materials can be used in the hole transport layer.

Examples of materials that can be used in the hole injection layer and the hole transport layer include aromatic amine compounds (such as N,N'-di(naphthyl-1-yl)-N,N'-diphenyl Aromatic diamines such as benzidine (α-NPD)), phthalocyanine compounds, thiophene compounds (such as thiophene-based conductive polymers (such as poly(3,4-ethylenedioxythiophene)): poly(4- Styrene sulfonate) (PEDOT: PSS), etc.).

[Electron Transport Layer, Electron Injection Layer] Materials used in the electron transport layer and the electron injection layer include, for example, phenanthroline derivatives, bipyridine derivatives, nitro-substituted fluorine derivatives, and diphenylbenzoquinone derivatives. substances, thiopyran dioxide derivatives; fused ring tetracarboxylic anhydrides of naphthalene, perylene, etc.; carbodiimides, benzylidene methane derivatives, anthraquinone dimethane and anthrone derivatives, oxadiazole Derivatives, thiadiazole derivatives, benzimidazole derivatives (such as 2,2',2"-(1,3,5-phenyltriyl)benzimidazole (1-phenyl-1H-benzimidazole) (TPBi )), quinoxaline derivatives, aluminum complexes (for example, bis(2-methyl-8-quinoline)-4-(phenylphenol)aluminum (BAlq)), etc. In addition, the above embodiments can also be used of organic electronic materials.

[Cathode] As the cathode material, for example, metals or metal alloys such as Li, Ca, Mg, Al, In, Cs, Ba, Mg/Ag, LiF, and CsF can be used.

[Anode] As an anode material, for example, metal (for example, Au) or other conductive materials can be used. Examples of other materials include oxides (for example, ITO: indium oxide/tin oxide), conductive polymers (for example, polythiophene-polystyrene sulfonic acid mixture (PEDOT: PSS)), and the like.

[Substrate] As the substrate, glass, plastic, etc. can be used. The substrate is preferably transparent. Furthermore, a flexible substrate (flexible substrate) is preferred. As the substrate, quartz glass, a translucent resin film, etc. can be preferably used.

Examples of the resin film include films made of the following resins: polyethylene terephthalate, polyethylene naphthalate, polyether ester, polyether imide, polyether ether ketone, polyphenylene Sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, cellulose acetate propionate, etc.

When a resin film is used, the resin film can be coated with an inorganic substance such as silicon oxide or silicon nitride in order to suppress the penetration of water vapor, oxygen, etc.

[Emission color] The emission color of the organic EL element is not particularly limited. White organic EL elements are preferred because they can be used in various lighting fixtures such as home lighting, interior lighting, clocks, and liquid crystal backlights.

As a method of forming a white organic EL element, a method of using a plurality of luminescent materials to simultaneously emit light of a plurality of luminescent colors and mixing the colors can be used. The combination of multiple luminescent colors is not particularly limited, and examples include a combination of luminescence maximum wavelengths of three colors: blue, green, and red; a combination of luminescence of two colors: blue and yellow, yellow-green and orange. Extremely large wavelength combinations, etc. The control of luminescent color can be achieved by adjusting the type and amount of luminescent materials.

<Display element, lighting device, display device> A display element according to an embodiment of the present invention includes the organic EL element according to the above-mentioned embodiment. For example, by using an organic EL element as an element corresponding to each pixel of red, green, and blue (RGB), a color display element can be obtained. The pixel formation methods include: simple matrix type, which uses electrodes arranged in a matrix to directly drive each organic EL element arranged on the panel; and active matrix type, which arranges thin film transistors on each element and be driven.

Furthermore, a lighting device according to an embodiment of the present invention includes the organic EL element according to the embodiment of the present invention. Furthermore, a display device according to an embodiment of the present invention includes a lighting device and a liquid crystal element as a display means. For example, the display device can be a display device, that is, a liquid crystal display device that uses the lighting device according to the embodiment of the present invention as a backlight and uses a conventional liquid crystal element as a display means. [Example]

Hereinafter, the present invention will be further explained in detail through examples, but the present invention is not limited to the following examples.

<1-1> Preparation of charge-transporting polymer (preparation of Pd catalyst) In a glove box under a nitrogen atmosphere, add ginseng (diphenylmethylacetone) dipalladium (73.2 mg, 80 μmol) at room temperature. Weigh into sample tube and add anisole (15 mL) and stir for 30 minutes. Similarly, ginseng(tertiary butyl)phosphine (129.6 mg, 640 μmol) was weighed into the sample tube, and anisole (5 mL) was added, followed by stirring for 5 minutes. The solutions were mixed and stirred at room temperature for 30 minutes to prepare a catalyst. All solvents were degassed by bubbling nitrogen for more than 30 minutes before use.

(Charge transport polymer 1) The following monomer L1 (5.0 mmol), the following monomer B1 (2.0 mmol), the following monomer T1a (4.0 mmol), and anisole were added to a three-neck round-bottomed flask. (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). After stirring for 30 minutes, 10% tetraethylammonium hydroxide aqueous solution (20 mL) was added. All solvents were degassed by bubbling nitrogen for more than 30 minutes before use. The mixture was heated to reflux for 2 hours. All operations so far have been performed under nitrogen flow.

Monomer L1 Monomer B1 Monomeric T1a

After the reaction, the organic layer was washed with water, and the organic layer was poured into methanol-water (9:1). The generated precipitate was recovered by suction filtration and washed with methanol-water (9:1). The precipitate obtained was dissolved in toluene and reprecipitated from methanol. The obtained precipitate was recovered by suction filtration, dissolved in toluene, and then a metal adsorbent ("Triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer" manufactured by Strem Chemicals) was added. The amount per 100 mg of the precipitate was 200mg) and stir overnight.

After the stirring is completed, the metal adsorbent and insoluble matter are filtered out, and the filtrate is concentrated using a rotary evaporator. The concentrated solution was dissolved in toluene and reprecipitated from methanol-acetone (8:3). The generated precipitate was recovered by suction filtration and washed with methanol-acetone (8:3). The obtained precipitate was vacuum-dried, and the charge-transporting polymer 1 was obtained.

The obtained charge transporting polymer 1 had a number average molecular weight of 13,600 and a weight average molecular weight of 72,800. Charge transport polymer 1 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1) and structural unit T1 (derived from monomer T1a), and the proportions of each structural unit are in order: 45.5%, 18.2% and 36.3%.

The number average molecular weight and the weight average molecular weight are measured by GPC (in terms of polystyrene) using tetrahydrofuran (THF) as the eluent. The measurement conditions are as follows. Liquid delivery pump: L-6050, Hitachi High-Technologies Co., Ltd. UV-Vis detector: L-3000, Hitachi High-Technologies Co., Ltd. Column: Gelpack (registered trademark), GL-A160S/GL-A150S, Hitachi Chemical Co., Ltd. Eluate: THF (for HPLC, without stabilizer), Wako Pure Chemical Industries, Ltd. Flow rate: 1mL/min Column temperature: room temperature Molecular weight standard material: standard polystyrene

(Charge transport polymer 2) In a three-neck round-bottomed flask, the above-mentioned monomer L1 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the following monomer T1b (4.0 mmol), and anisole (20 mL) were added. ), and further add the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 2 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 2 had a number average molecular weight of 24,700 and a weight average molecular weight of 49,100. Charge transport polymer 2 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1) and structural unit T1 (derived from monomer T1b), and the proportions of each structural unit are in order: 45.5%, 18.2% and 36.3%.

Monomeric T1b

(Charge transport polymer 3) The above-mentioned monomer L1 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the following monomer T1c (4.0 mmol), and anisole (20 mL) were added to a three-neck round-bottomed flask. ), and further add the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 3 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 3 had a number average molecular weight of 15,100 and a weight average molecular weight of 58,200. Charge transport polymer 3 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1) and structural unit T1 (derived from monomer T1c), and the proportions of each structural unit are in order: 45.5%, 18.2% and 36.3%.

Monomeric T1c

(Charge transport polymer 4) In a three-necked round-bottomed flask, the above-mentioned monomer L1 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the above-mentioned monomer T1c (1.0 mmol), and the following monomer T2a (3.0 mmol), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 4 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 4 had a number average molecular weight of 15,700 and a weight average molecular weight of 56,400. Charge transport polymer 4 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2a ), and the proportions of each structural unit are 45.5%, 18.2%, 9.1% and 27.2% in sequence.

Monomeric T2a

(Charge transport polymer 5) The above-mentioned monomer L1 (5.0mmol), the above-mentioned monomer B1 (2.0mmol), the above-mentioned monomer T1c (1.2mmol), the above-mentioned monomer T2a (2.8mmol) were added to a three-neck round-bottomed flask. ), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 5 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 5 had a number average molecular weight of 12,800 and a weight average molecular weight of 41,800. Charge transport polymer 5 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2a ), and the proportions of each structural unit are 45.5%, 18.2%, 10.9% and 25.4% in sequence.

(Charge transport polymer 6) The above-mentioned monomer L1 (5.0mmol), the above-mentioned monomer B1 (2.0mmol), the above-mentioned monomer T1c (1.6mmol), the above-mentioned monomer T2a (2.4mmol) were added to a three-neck round-bottomed flask. ), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 6 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 6 had a number average molecular weight of 12,600 and a weight average molecular weight of 41,000. Charge transport polymer 6 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2a ), and the proportions of each structural unit are 45.5%, 18.2%, 14.5% and 21.8% in sequence.

(Charge transport polymer 7) The above-mentioned monomer L1 (5.0mmol), the above-mentioned monomer B1 (2.0mmol), the above-mentioned monomer T1c (2.0mmol), the above-mentioned monomer T2a (2.0mmol) were added to a three-neck round-bottomed flask. ), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 7 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 7 had a number average molecular weight of 13,500 and a weight average molecular weight of 42,100. Charge transport polymer 7 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2a ), and the proportions of each structural unit are 45.5%, 18.2%, 18.15% and 18.15% in sequence.

(Charge transport polymer 8) In a three-neck round-bottomed flask, the above-mentioned monomer L1 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the above-mentioned monomer T1c (2.0 mmol), and the following monomer T2b (2.0 mmol), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 8 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 8 had a number average molecular weight of 13,000 and a weight average molecular weight of 45,100. Charge transport polymer 8 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2b ), and the proportions of each structural unit are 45.5%, 18.2%, 18.15% and 18.15% in sequence.

Monomeric T2b

(Charge transport polymer 9) The above-mentioned monomer L1 (5.0mmol), the above-mentioned monomer B1 (2.0mmol), the above-mentioned monomer T1c (1.0mmol), the above-mentioned monomer T2b (3.0mmol) were added to a three-neck round-bottomed flask. ), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 9 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 9 had a number average molecular weight of 12,300 and a weight average molecular weight of 55,800. Charge transport polymer 9 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2b ), and the proportions of each structural unit are 45.5%, 18.2%, 9.1% and 27.2% in sequence.

(Charge transport polymer 10) In a three-neck round-bottomed flask, the above-mentioned monomer L1 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the above-mentioned monomer T1c (2.0 mmol), and the following monomer T2c (2.0 mmol), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 10 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 10 had a number average molecular weight of 15,700 and a weight average molecular weight of 45,100. The charge transport polymer 10 has a structural unit L (derived from the monomer L1), a structural unit B (derived from the monomer B1), a structural unit T1 (derived from the monomer T1c), and a structural unit T2 (derived from the monomer T2c). ), and the proportions of each structural unit are 45.5%, 18.2%, 18.15% and 18.15% in sequence.

Monomeric T2c

(Charge transport polymer 11) The above-mentioned monomer L1 (5.0mmol), the above-mentioned monomer B1 (2.0mmol), the above-mentioned monomer T1c (1.0mmol), the above-mentioned monomer T2c (3.0mmol) were added to a three-neck round-bottomed flask. ), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 11 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 11 had a number average molecular weight of 16,400 and a weight average molecular weight of 46,900. Charge transport polymer 11 has structural unit L (derived from monomer L1), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2c). ), and the proportions of each structural unit are 45.5%, 18.2%, 9.1% and 27.2% in sequence.

(Charge transport polymer 12) The following monomer L2 (5.0 mmol), the above-mentioned monomer B1 (2.0 mmol), the above-mentioned monomer T1c (1.0 mmol), the above-mentioned monomer T2a (3.0 mmol), and anisole (20 mL), and further added the previously prepared Pd catalyst solution (7.5 mL). Then, the charge transporting polymer 12 is prepared in the same manner as when the charge transporting polymer 1 was prepared.

The obtained charge transporting polymer 12 had a number average molecular weight of 18,900 and a weight average molecular weight of 49,100. Charge transport polymer 12 has structural unit L (derived from monomer L2), structural unit B (derived from monomer B1), structural unit T1 (derived from monomer T1c), and structural unit T2 (derived from monomer T2a ), and the proportions of each structural unit are 45.5%, 18.2%, 9.1% and 27.2% in sequence.

Monomer L2

The monomers used in preparing charge transport polymers 1 to 12 are summarized in Table 1 below. In the table, the monomer marked (*) has a structure represented by formula (I).

[Table 1]

<1-2> Evaluation of charge-transporting polymers Table 2 shows the thermogravimetric reduction rate of each charge-transporting polymer 1 to 12 when heated to 300°C. Here, the thermogravimetric reduction rate (mass %) is measured using a thermogravimetric differential thermal analysis (TG-DTA) device ("DTG-60/60H" manufactured by Shimadzu Corporation) at 5°C/min in air. The value measured when 10 mg of the charge-transporting polymer was heated to 300°C under the heating conditions. The smaller the measured value is, the more excellent the heat resistance is.

[Table 2]

From the results shown in Table 2, it can be seen that compared with the charge transport polymers 1 and 2 that do not have the above-mentioned specific structural site, the charge transport polymers 3 to 12 having the specific structural site represented by the formula (I) perform better when heated. The thermal weight loss rate at 300°C is significantly less, and it has excellent heat resistance. Therefore, by using a charge-transporting polymer having a specific structural moiety represented by formula (I), an organic electronic material having excellent heat resistance can be provided. Furthermore, among the above-mentioned charge transport polymers 3 to 12, polymers 4 to 9 and 12 have better heat resistance than polymer 3. From this, it can be seen that by increasing the ratio of the ring structure contained in the molecule, Can further improve heat resistance.

<2-1> Preparation of organic hole device (HOD) (Example 1) Under the atmosphere, the previously prepared charge transport polymer 3 (10.0 mg), the following polymerization initiator 1 (0.5 mg) and toluene were mixed (2.3 mL) were mixed to prepare an ink composition. The ink composition was spin-coated on a glass substrate patterned with ITO to a width of 1.6 mm at a rotation speed of 3000 min ^{- 1} , and then heated at 200°C for 30 minutes on a hot plate to harden it to form holes. Implantation layer (100nm).

Polymerization initiator 1

Move the glass substrate obtained above to a vacuum evaporator, and sequentially deposit α-NPD (20nm) and Al (100nm) films on the hole injection layer, and then perform sealing treatment. To make organic hole HOD1.

Use the same method as when making organic HOD1, spin-coat the ink composition on the glass substrate after patterning ITO into a width of 1.6 mm at a rotation number of 3000 min ^{- 1} , and heat it on a hot plate at 200°C for 30 minutes . Organic HOD2 was produced in the same manner as when organic HOD1 was produced, except that the hole injection layer was further heated at 230° C. for 30 minutes in a nitrogen atmosphere.

(Example 2) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 4. , to make each organic HOD.

(Example 3) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 5. , to make each organic HOD.

(Example 4) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 6. , to make each organic HOD.

(Example 5) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 7. , to make each organic HOD.

(Example 6) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 8. , to make each organic HOD.

(Example 7) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 9. , to make each organic HOD.

(Example 8) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 10. , to make each organic HOD.

(Example 9) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 11. , to make each organic HOD.

(Example 10) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 12. , to make each organic HOD.

(Comparative Example 1) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 1. , to make each organic HOD.

(Comparative Example 2) The formation step of the hole injection layer in the organic HODs 1 and 2 of Example 1 was performed in the same manner as in Example 1, except that the charge transport polymer 3 was changed to the charge transport polymer 2. , to make each organic HOD.

<2-2> Evaluation of organic HOD (hole injection layer) A voltage was applied to each of the organic HOD produced in Examples 1 to 10 and Comparative Examples 1 and 2 described above. As a result, it was found that electric current flows in any of the organic HODs, and it was confirmed that the organic HOD has a hole-injecting function. Furthermore, the driving voltage was measured for each organic HOD. The measurement results are shown in Table 3.

<2-3> Evaluation of the curability of the ink composition The remaining film rate of the organic thin film was measured according to the following method to evaluate the curability of the ink composition used to form the hole injection layer. The measurement results are shown in Table 3.

(Measurement method of residual film ratio) Each charge transport polymer (10.0 mg) used in Examples 1 to 10 and Comparative Examples 1 and 2 was dissolved in toluene (1.991 μL) to obtain a polymer solution. Furthermore, the previously shown polymerization initiator 1 (0.309 mg) was dissolved in toluene (309 μL) to obtain a polymerization initiator solution. The obtained polymer solution and the polymerization initiator solution are mixed to prepare an ink composition.

The ink composition was spin-coated on a quartz glass plate at room temperature (25° C.) at a rotation speed of 3000 min ⁻¹ to form ^an organic thin film. Next, the quartz glass plate with the organic thin film was heated on a hot plate at 200° C. for 30 minutes to harden the organic thin film. Then, the quartz glass plate was picked up with tweezers and immersed in a 200 mL beaker filled with toluene (25° C.), and then the quartz glass plate was vibrated back and forth 10 times in the thickness direction of the quartz glass plate within 10 seconds.

From the ratio of the absorbance (Abs) of the maximum absorption wavelength (λmax) in the UV-vis spectrum of the organic film before and after immersion, the remaining film rate of the organic film was calculated according to the following formula. The higher the residual film rate is, the better the curability of the ink composition is.

Remaining film rate (%) = Abs of the organic film after immersion/Abs of the organic film before immersion × 100 In the measurement of absorbance, a spectrophotometer (U-3310 manufactured by Hitachi, Ltd.) was used to measure the organic film. The absorbance of the film was measured at the maximum absorption wavelength in the wavelength range of 300 to 500 nm.

[table 3]

Driving voltage 1: For organic HOD1 (heated at 200°C for 30 minutes), the value measured at a current density of 300 mA/cm.

Driving voltage 2: Value measured at a current density of 300 mA/cm for organic HOD2 (heated at 200°C for 30 minutes and further heated at 230°C for 30 minutes).

The rising value of the driving voltage: the value of the driving voltage 2 (V) - the driving voltage 1 (V).

As shown in Table 3, the increase in driving voltage of the organic HODs of Examples 1 to 10 was smaller than that of Comparative Examples 1 and 2. That is, from the viewpoint of the constituent material of the hole injection layer, it is found that by using an organic electronic material including a charge-transporting polymer with a small thermogravimetric reduction rate (excellent heat resistance), it is possible to suppress the formation of the hole injection layer after high-temperature heating. The drive voltage rises. From this, it can be seen that by using the organic electronic material according to the embodiment of the present invention, thermal degradation of the organic layer can be suppressed. In addition, it was found that the organic electronic materials according to the embodiments of the present invention (Examples 1 to 10) all have excellent curability and are suitable for wet processes.

<3-1> Preparation of an organic EL element. An organic EL element including a hole injection layer formed using the previously prepared charge transport polymer was produced, and its performance was evaluated.

(Example 11) The charge transport polymer 3 (10.0 mg), the above-mentioned polymerization initiator 1 (0.5 mg), and toluene (2.3 mL) were mixed in an air atmosphere to prepare an ink composition. The ink composition was spin-coated on a glass substrate patterned with ITO to a width of 1.6 mm at a rotation speed of 3000 min ^{- 1} , and then heated at 200°C for 10 minutes on a hot plate to harden. It was further heated at 230° C. for 30 minutes in a nitrogen atmosphere to form a hole injection layer (30 nm).

The above-mentioned glass substrate with the hole injection layer is moved to a vacuum evaporator, and α-NPD (40nm) and CBP: Ir (ppy) ₃ (94: 6, 30nm), BAlq (10nm), TPBi (30nm), LiF (0.8nm), and Al (100nm) film formation. Then, a sealing process is performed to produce an organic EL element.

(Example 12) The formation step of the hole injection layer in the organic EL element of Example 11 was performed in the same manner as in Example 11, except that the charge transport polymer 3 was changed to the charge transport polymer 4. to produce organic EL components.

(Example 13) The formation step of the hole injection layer in the organic EL element of Example 11 was performed in the same manner as in Example 11, except that the charge transport polymer 3 was changed to the charge transport polymer 12. to produce organic EL components.

<3-2> Evaluation of organic EL elements When a voltage was applied to the organic EL elements obtained in Examples 11 to 13, green light emission was confirmed in all of them. For each element, the driving voltage and luminous efficiency at a luminous brightness of 5000 cd/m ² and the luminous lifetime (brightness half-life time) at an initial luminance of 5000 cd/m ² were measured. The measurement results are shown in Table 4.

[Table 4]

The organic EL elements of Examples 11 to 13 have a hole injection layer obtained by applying a high-temperature baking process. All organic EL elements achieve excellent results in terms of driving voltage, luminous efficiency, and luminous lifetime. That is, it was found that by using a charge-transporting polymer with excellent heat resistance as the hole injection layer material, thermal deterioration can be suppressed and hole injection characteristics can be maintained.

As described above, the effects of the embodiments of the present invention have been demonstrated through the Examples. However, according to the present invention, it is not limited to the charge transport polymer used in the embodiments. As long as other charge transport polymers are used without departing from the scope of the present invention, the same effect can still be obtained. In addition, it is found that by using the organic electronic material of the present invention, the deterioration of the organic layer can be suppressed in other organic electronic devices, not limited to the organic EL devices shown in the examples.

1‧‧‧Light-emitting layer 2‧‧‧Anode 3‧‧‧Hole injection layer 4‧‧‧Cathode 5‧‧‧Electron injection layer 6‧‧‧Hole transport layer 7‧‧‧Electron transport layer 8‧‧‧ substrate

FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element according to an embodiment of the present invention.

Domestic storage information (please note in order of storage institution, date and number) None

Overseas deposit information (please note in order of deposit country, institution, date and number) None

1‧‧‧Light-emitting layer

2‧‧‧Anode

3‧‧‧Hole injection layer

4‧‧‧Cathode

5‧‧‧Electron injection layer

6‧‧‧Hole transport layer

7‧‧‧Electron transport layer

8‧‧‧Substrate

Claims (19)

An organic electronic material, which contains a charge transport polymer, the charge transport polymer has a structure branching in more than three directions, and the weight average molecular weight is greater than 40,000; the aforementioned charge transport polymer has a structure that branches in more than three directions The trivalent or higher structural unit of the branch part of the directionally branched structure, the divalent structural unit having charge transport properties, the monovalent structural unit represented by the following formula (I-3), and the following formula (II ) represents a monovalent structural unit; the thermogravimetric reduction rate of the charge-transporting polymer when heated to 300°C is 5% or less; -Ar-O-(CH ₂ ) _n -Z (I-3) formula ( In I-3), Ar represents an aryl or heteroaryl group having 2 to 30 carbon atoms, Z represents a substituted or unsubstituted polymerizable functional group, and n is 1 to 10; -Ar-J-R1 ( II) In formula (II), Ar represents an aryl group or heteroaryl group having 2 to 30 carbon atoms, and J represents a single bond, an ester bond, or a structure remaining after removing one hydrogen atom from the amine group. The coupling group -NR-, in the aforementioned coupling group -NR-, R is a phenyl group, and R1 represents a cyclic alkyl group having 3 to 30 carbon atoms. The organic electronic material as described in claim 1, wherein the former The polymerizable functional group includes at least one selected from the group consisting of an oxetanyl group, an epoxy group, a vinyl group, an acrylyl group, and a methacrylyl group. The organic electronic material according to claim 1, wherein the charge transport polymer is a hole injection layer material. The organic electronic material of claim 1, wherein the charge-transporting polymer is selected from the group consisting of an aromatic amine structure, a carbazole structure, a thiophene structure, a bithiophene structure, a benzene structure, a phenoxazine structure, and a fluorine structure. At least 1 structure in the group. The organic electronic material according to claim 1, further comprising a polymerization initiator. The organic electronic material according to claim 5, wherein the aforementioned polymerization initiator includes a cationic polymerization initiator. The organic electronic material according to claim 6, wherein the cationic polymerization initiator includes an onium salt. The organic electronic material according to claim 1, further comprising a solvent. The organic electronic material according to claim 8, wherein the aforementioned solvent is a non-polar solvent. An organic layer formed of the organic electronic material described in any one of claims 1 to 9. An organic electronic component comprising the description of claim 10 of the organic layer. An organic electroluminescent element comprising the organic layer described in claim 10. The organic electroluminescent element according to claim 12, which has a light-emitting layer containing a phosphorescent material. The organic electroluminescent element according to claim 12, which has a light-emitting layer containing a thermally activated delayed fluorescent material. The organic electroluminescent element according to claim 12, further comprising a flexible substrate. The organic electroluminescent element according to claim 12, further comprising a resin film substrate. A display element provided with the organic electroluminescent element according to claim 12. A lighting device provided with the organic electroluminescent element according to claim 12. A display device including the lighting device according to claim 18 and a liquid crystal element as a display means.